Chevy Camaro 305 Engine Rebuild - My Generation Camaro, Part V

A Rebuild, Ported Heads, and a Cam for Our Stormin' 305

Step By Step

Instead of just bolting the heads and cam into the old motor, Moore decided to spend $500 and do a quickie rebuild. The old 305 had already been rebuilt once, but the 0.030-over 305 cast pistons looked great.

In the previous installment we detailed the Slovers porting work performed on the World Products S/R Torquer 305 heads. The iron performance replacement heads feature 1.94/1.50-inch valves with a 58cc chamber.

Starting in 1987, Chevy converted to hydraulic roller camshafts. We chose a Crane CompuCam roller with 0.407/0.429-inch lift to make more power that is also emissions-legal to keep the smog police at arms length.

Dragstrip testing isnt always the rosy picture it should be. The Camaro picked up another 0.43 second, but did so in miserable conditions with a 20-mph headwind. We assume thats why the e.t. improved while the trap speed stagnated.

Our pocket-change performer Camaro is back. After a quick hiatus that Tim Moore spent thrashing on a new motor, we're now quicker, faster, and more powerful than before. We've got a lot to cover in this installment, so let's jump right into the gritty details.

At the close of Part IV, we had just finished assembling the Slover's-ported World Products S/R Torquer 305 heads. Combined with the new Crane hydraulic roller camshaft, we anticipated pulling off some better numbers at the dragstrip. Moore decided the job would be easier if he pulled the engine out of the car. Once the greasy monster was on a stand, we decided that since the engine was stripped down to a mere short-block, it was the perfect time for a quick rebuild. Moore decided our budget could afford new pistons, rings, bearings, and some machine work if we kept the tricks to a minimum. That's where our plans went awry.

The first task was to clean and Magnaflux the block at Jim Grubbs Motorsports (JGM). That's when the JGM crew discovered the cracked block. So then it was off to find another block. Fortunately, we found a clean, standard bore, roller-cam 305 block for $75 and were soon back at JGM's machine room. Our good fortune continued, because our original engine had been rebuilt, using 0.030-over pistons. So we decided to bore and hone the block to fit the existing pistons. We then hustled over to Performance Automotive Warehouse (PAW) where we picked up a Deluxe Engine Rebuild kit that included a set of 0.010-under rod and main bearings, Hastings 5/64-inch rings, a timing chain and gear set, and a complete ROL gasket set. To this we added a set of cam bearings and a freeze-plug set. Moore also discovered a few wasted rocker arms, but rather than buy a whole new set, he scrounged the four we needed from a friend. All this set us back over $500, including the machine work, but we felt that we had a better chance to make more power if the engine could seal up the additional air we intended to stuff into the cylinders. Besides, how often is it that you can rebuild an engine for around $500?

Since most budget artists don't degree the camshaft, we decided to do the same and just aligned the marks on the timing gears and bolted it together along with the used lifters that Moore disassembled and cleaned. One advantage of roller lifters is that if they are in good shape, you can reuse them on a new cam without damage to the cam. The only other addition was purchasing a set of steel-shim Fel-Pro head gaskets, because the S/R Torquer heads require a 4-inch bore gasket as opposed to the gasket designed for the 305's smaller 3.736-inch bore.

Once the 305 was back in the car, Moore finished off the installation reusing all the previous parts, including the Edelbrock Performer aluminum intake, Edelbrock headers, and the Flowmaster exhaust system. Now we had a fresh engine to push through the 3.73 rear gears and rebuilt Posi. After a quick pressure lube and engine break-in, Moore took the Camaro for a test ride and pronounced the Camaro up on power and fun to drive. Now it was time for the dragstrip test.

Our previous best had been a 15.82 at 86.74 mph before the heads, cam, and short-block rebuild. Our original goal was a lofty 14.99 with a target of 90 mph. Frankly, we doubted whether we could achieve that, so we figured 15.20 at 88 mph was attainable. We drove the Camaro up to Los Angeles County Raceway (LACR) on a Wednesday grudge night hoping the cooler night air would help our cause. But as is usually the case with the high desert, as soon as the sun went down the wind picked up. Our handy PerformAir weather station from our pals at Helmet City told us the density altitude was a less-than-desirable 4,700 feet. With the headwind, we were certainly swimming upstream.

Moore made several passes experimenting with shift points between 5,000 and 5,500 rpm. It seemed that our little 305 ran best when shifted at 5,200 rpm and running through the lights at the top end at just over 4,200 rpm. Our best time of the night was a corrected 15.39 at 87.28 mph running into a 20 to 25 mph headwind. As you can see from the Quarter-Mile Tales sidebar, we picked up almost a half-second from the previous best, but the mph improvement was barely a half-mph. We chalked this up to the headwind and ugly atmospheric conditions. We've discussed the possibility of driving to the San Diego area to run the Camaro at Carlsbad Raceway where the air is much better. This should be worth roughly another 0.20 to 0.30 second compared to our existing corrected times from LACR. It's worth mentioning that the correction factor for LACR only accounts for the 3,000-foot altitude of the dragstrip, not for the high summertime temperatures. It's possible that the Camaro could run a low 15 pass with a trap speed well over 90 mph and good conditions. But to put this in perspective, since our initial baseline, we've improved the e.t. and speed by 2.06 seconds and 8.64 mph. Not bad for a small pile of bolt-on parts.

Have we taken this Camaro as far as we can go? Not even close. We've already ordered the tunable Nitrous Oxide Systems Super PowerShot plate nitrous system for the Camaro, and we'll bolt that on next month to see what it's worth. We'll show you how to bolt on this system along with our test results. It's possible the Camaro could squeeze into the low 13s with a load of nitrous, but this will take a set of sticky Mickey Thompson ET Street rear tires as well to help with traction. We're also going to have the TH700-R4 automatic rebuilt with a B&M trans kit to help the trans stand up to the added power.

From a budget standpoint, we're looking pretty good. We have a 15-second Camaro, and all the bills totaled only put us back $3,903. Add the nitrous system, sticky rear tires, a trans rebuild, and a couple of refills on the nitrous bottle and we're estimating the total cost could hit around $5,100. All of this is still just conjecture, but a low 13-second car for $5,000 qualifies as a screamin' good deal, especially when you consider that it includes the price of the car. But you'll have to wait to see if we are able to pull all this off.

Instead of just bolting the heads and cam into the old motor, Moore decided to spend $500 and do a quickie rebuild. The old 305 had already been rebuilt once, but the 0.030-over 305 cast pistons looked great.

Once JGM completed the 0.030-inch overbore and torque-plate honing, Moore dropped the crank in place and did some final rod-journal measurements to ensure adequate bearing clearance.

PAW supplied the Deluxe Engine Rebuild kit that included ROL gaskets, Hastings 5/64-inch piston rings, and a Clevite 77 rod and main bearing set. We also added PAW cam bearings and a Pioneer freeze-plug set.

The used pistons from the old 305 cleaned up rather nicely and Moore used a ring spreader to install the Hastings rings.

Inspecting the old engine as it came apart revealed four rocker arms that were abusing the valve tips. This one is the worstthe valve tip had broken.

In the previous installment we detailed the Slovers porting work performed on the World Products S/R Torquer 305 heads. The iron performance replacement heads feature 1.94/1.50-inch valves with a 58cc chamber.

Starting in 1987, Chevy converted to hydraulic roller camshafts. We chose a Crane CompuCam roller with 0.407/0.429-inch lift to make more power that is also emissions-legal to keep the smog police at arms length.

Dragstrip testing isnt always the rosy picture it should be. The Camaro picked up another 0.43 second, but did so in miserable conditions with a 20-mph headwind. We assume thats why the e.t. improved while the trap speed stagnated.

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Check out this Chevy High Performance article about how we install World Products iron S/R Torquer 305 heads, a Crane CompuCam hydraulic-roller camshaft and a pocket-porting job on the 1987 Chevy Camaro. » Read More